PubMed Health⌕ Search

Biomedical subjects

A Calame

Publications and source records attributed to A Calame.

At least 37 records · Page 2Linked to original sources

Water, energy and early postnatal growth in preterm infants.

Non-invasive methods, including stable isotope techniques, indirect calorimetry, nutritional balance and skinfold thickness, have given a new insight into early postnatal growth in neonates. Neonates and premature infants in particular, create an unusual opportunity to study the fluid and metabolic adaptation to extrauterine life because their physical environment can be controlled, fluid and energy balance can be measured and the link between metabolism and the energetics of their postnatal growth can be assessed accurately. Thus the postnatal time course of total body water, heat production, energy cost of growth and composition of weight gain have been quantified in a series of "healthy" low-birth-weight premature infants. These results show that total body water is remarkably stable between postnatal days 3-21. Energy expenditure and heat production rates increase postnatally from mean values of 40 kcal/kg/day during the first week to 60 kcal/kg/day in the third week. An apparent energy balance deficit of 180 kcal/kg can be ascribed to premature delivery. The cost of protein metabolism is the highest energy demanding process related to growth. The fact that nitrogen balance becomes positive within 72 h after birth places the newborn in a transitional situation of dissociated balance between energy and protein metabolism during early postnatal growth: skinfold thickness, dry body mass and fat decrease, while there is a gain in protein and increase in supine length. This particular situation ends during the second postnatal week and soon thereafter the rate of weight gain matches statural growth. The goals of the following review are to summarize data on total body water and energy metabolism in premature infants and to discuss how they correlate with physiological aspects of early postnatal growth.

Body Composition↗

[Extremely premature infants: what is their future? Lausanne experience 1982-1992].

This study describes neonatal mortality and morbidity as well as the neuropsychological outcome of extremely-low-birth-weight infants (less than 1000 grams) born between 1/1/1982 and 12/31/1992. The number of preterm infants admitted to the neonatal unit has increased over the last ten years. If neonatal mortality remains high, the prognosis of these immature children is favourable and depends on close collaboration between obstetricians and neonatologists and on the quality of perinatal care.

Brain Damage, Chronic↗

Plasma/serum protein patterns in human fetuses and infants: a study by high-resolution two-dimensional polyacrylamide gel electrophoresis.

Plasma/serum proteins of fetal blood samples (N = 88) obtained under ultrasound guidance between the 18th and the 39th week of pregnancy, of blood samples collected from premature infants (N = 19), newborns at term (N = 20) and children of less than 5 years of age (N = 55) were analysed by high-resolution two-dimensional polyacrylamide gel electrophoresis. By comparison with adult 'reference' protein maps, tens of different proteins (and some of their genetic variants) were identified on the electrophoretograms. After the 18th week of gestation, albumin, transferrin, Factor B, glu- and lys-plasminogen, antithrombin III, Gc-globulin, alpha 1-antitrypsin, alpha 2-HS-glycoprotein, several apolipoproteins (apo A-I, A-II, A-IV, C-II, C-III, D, E, J), retinol-binding protein, transthyretin and alpha-fetoprotein could be observed. During intrauterine life, the size of the spots corresponding to alpha-fetoprotein progressively decreased, whereas the protein pattern globally showed an increase in the number and in the size of the spots. These modifications were particularly apparent in the regions of the electrophoretograms restricted to the heavy and light chains of IgG and to alpha 1-antichymotrypsin. In addition, we observed an unidentified fetal polypeptide characterized by an apparent molecular weight (M(r)) of 46 kDa (P46) and a pI of 5.0. P46 was present in all fetuses and all infants of less than 2 years of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Epidemiology of vertically transmitted HIV-1 infection in Switzerland: results of a nationwide prospective study. Swiss Neonatal HIV Study Group.

A nationwide study involving 286 children of human immunodeficiency virus (HIV)-infected mothers living in Switzerland has been performed with the participation of all paediatricians interested in HIV infection in the country. Of these children 201 could be followed up prospectively from birth up to a median age of 22 months. Prevalence of HIV infection in Swiss parturients was estimated at 0.1% and apparently remained stable from 1986 to 1989. Vertical transmission rate was estimated at 14%-20%. Variables of maternal or perinatal history were not associated with transmission rate. Transmission to pairs of siblings of the same mothers was discordant in 33% (6 of 18), with always the elder sibling being infected. Postneonatal mortality in infants of HIV-infected mothers followed up from birth was increased 15-fold over the general population with a very high incidence (2 in 100) of sudden infant death apparently unrelated to HIV infection.

Child↗

Monoclonal gammopathy in a 30 weeks old premature infant.

The occurrence of monoclonal gammopathy in childhood is extremely rare. This report describes the presence of a monoclonal immunoglobulin in a 30 week old premature infant, incidentally discovered by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) during an ongoing study of the plasma/serum protein development. Comparative analysis of the electrophoretogram of the infant with 'reference' protein maps revealed the presence of an 'abnormal' immunoglobulin light chain spot. A spot having an identical apparent molecular weight and isoelectric point was also detected after 2D-PAGE of the mother's plasma and its Protein-A purified immunoglobulin fraction. The observation of a monoclonal gammopathy in a premature infant, most likely transmitted from his mother, highlights the potential usefulness of 2D-PAGE in the clinical laboratory.

Blood Protein Electrophoresis↗

[Cardiac rhabdomyomatosis and Bourneville's tuberous sclerosis in the fetus. Apropos of 2 cases].

Two cases of cardiac rhabdomyoma discovered fortuitously at foetal ultrasonography gave rise to no obstructive cardiac signs or arrhythmias either in the antenatal or postnatal periods. These multiple tumours often observed in Bourneville's tuberous sclerosis orientated the clinical investigations to the diagnosis of this disease from the outset. MRI demonstrated cortical tubers and subependymal nodules in both cases. A retinal hamartoma was present in one case. No renal involvement could be detected by ultrasonic examination. No neurological or cardiovascular symptoms appeared during follow-up (20 and 4 months after birth). Investigations in the parents were negative, these two cases being sporadic forms of Bourneville's tuberous sclerosis. The functional prognosis is related to the neurological outcome. Doppler echocardiography would appear to be the best method of following up cardiac rhabdomyomas, and enabled the demonstration of partial regression of the largest tumour in one of these two cases. Cardiac MRI is also an excellent diagnostic tool. As it is usually performed at the same time as cerebral MRI, essential in the follow-up of Bourneville's tuberous sclerosis, it does not represent additional discomfort to the patient.

Adult↗

Significance of ultrasound appearances in the neurological development and cognitive abilities of preterm infants at 5 years.

The developmental outcome at 5 years of age was studied in 93 preterm infants who had been prospectively examined for peri-ventricular leucomalacia (PVL). Standardised neurological examination and developmental assessment, including tests of cognitive function, were carried out. Major sequelae (n = 10) could be ascribed in most cases to the presence of large PVL lesions. Children with normal scans (n = 51), with isolated haemorrhage (n = 15) and with post-haemorrhagic ventricular dilatation (n = 3) had a favourable prognosis. Patients with small focal PVL changes (n = 16) had lower cognitive abilities on the McCarthy scale and presented more abnormal neuromotor signs and more attention deficits when compared to children with normal scans and isolated haemorrhage. Small focal PVL changes seem therefore to interfere with development at 5 years of age and might represent a morphological marker of a more diffuse brain injury. This study demonstrated also the effect of socioeconomic status on outcome at the age of 5 years.

Cerebral Hemorrhage↗

Weekly intravenous administration of recombinant human erythropoietin in infants with the anaemia of prematurity.

To study the safety and efficacy of administering human recombinant erythropoietin (rHuEPO) to infants with anaemia of prematurity, a combined phase I/II trial of weekly intravenous injections for 4 weeks was undertaken. We treated 16 infants with 10, 25, 50, 100 or 200 units/kg body weight in groups of two to four patients per dose level. They were all born prematurely (mean gestational age: 29 weeks; range 27-32), had a mean post-natal age of 42 days (range: 25-59) and haemoglobin concentration of 87 g/l (range: 72-94) when treatment was started. Four patients (25%) needed a transfusion during the trial, one at day 7 treated with 10 units/kg and 3 at days 15, 25, 29 with 100 units/kg. In the others, a progressive rise in mean haemoglobin values was seen in each group after 21 days of treatment, without a dose-dependent effect. A positive change in absolute reticulocyte counts with a peak after 7-14 days of therapy was observed with low (25-50 units/kg) but not with higher doses, with a significant difference at day 14 between 25 and 100 units/kg (P less than 0.01). A dose-limiting severe neutropenia (absolute neutrophil count less than 0.5 x 10(9)/l) occurred transiently in five patients, with doses greater than 25 units/kg. No infectious complication and no sign of iron deficiency were observed. Weekly low doses of rHuEPO appear safe, convenient to administer and able to induce a reticulocytic response in infants with anaemia of prematurity. A phase III placebo-controlled trial is needed to confirm these results. Neutropenia associated with rHuEPO administration in infants might be related to their stage of human ontogeny.

Anemia, Neonatal↗

"Neonatal adaptation of energy and protein metabolism".

During the last decade, the development of "bedside" investigative methods, including indirect calorimetry, nutritional balance and stable isotope techniques, have given a new insight into energy and protein metabolism in the neonates. Neonates and premature infants especially, create an unusual opportunity to study the metabolic adaptation to extrauterine life because their physical environment can be controlled, their energy intake and energy expenditure can be measured and the link between their protein metabolism and the energetics of their postnatal growth can be assessed with accuracy. Thus, relatively abstract physiological concepts such as the postnatal timecourse of heat production, energy cost of growth, energy cost of physical activity, thermogenic effect of feeding, efficiency of protein gain, metabolic cost of protein gain and protein turnover have been quantified. These results show that energy expenditure and heat production rates increase postnatally from average values of 40 kcal/kgxday during the first week to 60 kcal/kgxday in the third week. This increase parellels nutritional intakes as well as the rate of weight gain. The thermogenic effect of feeding and the physical activity are relatively low and account only for an average of 5% each of the total heat production. The cost of protein turnover is the highest energy demanding process. The fact that nitrogen balance becomes positive within 72 hours after birth places the newborn in a transitional situation of dissociated balance between energy and protein metabolism: dry body mass and fat decrease while there is a gain in protein and increase in supine length. This particular situation ends during the second postnatal week and soon thereafter the rate of weight gain matches the statural growth. The goals of the following review are to summarize recent data on the physiological aspects of energy and protein metabolism directly related to the extrauterine adaptation, to describe experimental approaches which recently were adapted to the newborns in order to get "bedside results" and to discuss how far these results can help everyday's neonatal practice.

Adaptation, Physiological↗

Hidden intelligence of a multiply handicapped child with Joubert syndrome.

A child with Joubert syndrome (episodic hyperpnoea, abnormal eye-movements and ataxia) was followed from birth to eight years of age. Although severe mental retardation was suspected until approximately five years of age, unexpected and exceptional mental capacities were evident at later follow-up. Adequate testing and appropriate stimulation of children with such a severe early motor disorder are difficult, so they may give a false impression of mental retardation. The history of this child challenges the notion that mental retardation is part of Joubert syndrome.

Abnormalities, Multiple↗

Risk factors associated with the development of peri-intraventricular haemorrhage and periventricular leukomalacia.

81 preterm infants of 34 weeks' gestation or less were prospectively and sequentially examined by means of real-time ultrasound in order to identify which clinical risk factors might be associated with the development of peri-intraventricular haemorrhage (PVH) and periventricular leukomalacia (PVL). Infants were allocated in three groups: group A (n = 44): with normal scans; group B (n = 24): with isolated PVH, and group C (n = 13): with PVL. 28 obstetrical and neonatal factors were compared within the three groups using two methods of statistical analysis (2 x 2 chi 2 analysis and multivariate logistic regression analysis). Hyaline membrane disease, acidosis, pneumothorax and Apgar score at 10 min were statistically associated with PVH. The multivariate logistic regression analysis showed that need for resuscitation, hyaline membrane disease, acidosis and gestational age were the most important factors. Gestational age, seizures, hyaline membrane disease, apnoea with hypoxaemia and bradycardia were strongly associated with PVL. These results suggest that a low gestational age, the need for resuscitation and a respiratory distress syndrome with its consequences might lead to PVH, whereas a low gestational age, hypoxaemia and cardiocirculatory disturbances might decrease cerebral perfusion and result into PVL.

Cerebral Hemorrhage↗

Auditory brainstem responses and ultrasound changes in a high-risk infants population.

50 neonates were selected in a high perinatal risk population and examined by means of cerebral ultrasound (US) and auditory brainstem responses (ABR). They were allocated in 5 groups according to their US diagnosis (normal scans, isolated peri-intraventricular haemorrhage, large haemorrhage with associated lesions, hypoxic-ischaemic lesions in term neonates, miscellaneous disorders). ABR abnormalities were found in 40% of the infants. They were more frequent in neonates with cerebral lesions. Furthermore, the more extensive the cerebral lesions, the more severe the ABR abnormalities. Most of the ABR changes were of audiological type (severe: threshold greater than 80 dB [14%]; moderate: threshold less than or equal to 80 dB [20%]), whereas neurological abnormalities were rare (6%). The prognostic value of ABR appears in this study to depend on the possible recovery in the neonatal period. Severe hearing loss was associated either with an early death or with major handicaps. ABR represent the method of first choice for the detection of hearing loss in the Neonatal Unit, while they seemed to be of limited value in assessing brainstem function.

Brain Damage, Chronic↗

[Long-term prognosis for premature infants].

Recent advances in perinatology have been associated with a decrease in perinatal mortality among very low birth weight (VLBW) infants. However, only comprehensive follow-up programmes allow obstetricians and neonatologists to measure short-term and long-term effects of neonatal intensive care. In our experience, sequential brain ultrasonography together with serial neurological assessments during the neonatal period play an important role in the prediction of later neurodevelopmental outcome. Major sequelae are closely related to periventricular leukomalacia and extensive parenchymal haemorrhage. With improving knowledge of the physiopathology of cerebral damage, more effective preventive measures are now being taken. Nowadays, the incidence of major handicaps (5%) is steadily decreasing among VLBW survivors. Only a few comprehensive studies have regularly followed up preterm infants until school age. Our results showed that 17% of VLBW infants had minor neurodevelopmental abnormalities (visuomotor or motor disorders and language disorders) at 8 years of age. School failure was frequently found among children who presented the association of several neurodevelopmental abnormalities. Most of these developmental problems can be detected in preschool age, and early recognition may allow better counselling of parents and appropriate intervention. An optimistic attitude regarding the outcome in VLBW infants without cerebral lesions or associated neurodevelopmental abnormalities is certainly justified at the present time. These results emphasize the importance of optimal perinatal intensive care for VLBW infants.

Brain Damage, Chronic↗

Energy-nitrogen balances and protein turnover in small and appropriate for gestational age low birthweight infants.

The aim of the present study was to compare, under the same nursing conditions, the energy-nitrogen balance and the protein turnover in small for gestational age (SGA) and appropriate for gestational age (AGA) low birthweight infants. We compared 8 SGA's (mean +/- s.d.: gestational age 35 +/- 2 weeks, birthweight 1520 +/- 330 g) to 11 AGA premature infants (32 +/- 2 weeks, birthweight 1560 +/- 240 g). When their rate of weight gain was above 15 g/kg/d (17.6 +/- 3.0 and 18.2 +/- 2.6 g/kg/d, mean postnatal age 18 +/- 10 and 20 +/- 9 d respectively) they were studied with respect to their metabolizable energy intake, their energy expenditure, their energy and protein gain and their protein turnover. Energy balance was assessed by the difference between metabolizable energy and energy expenditure as measured by indirect calorimetry. Protein gain was calculated from the amount of retained nitrogen. Protein turnover was estimated by a stable isotope enrichment technique using repeated nasogastric administration of 15N-glycine for 72 h. Although there was no difference in their metabolizable energy intakes (110 +/- 12 versus 108 +/- 11 kcal/kg/d), SGA's had a higher rate of resting energy expenditure (64 +/- 8 versus 57 +/- 8 kcal/kg/d, P less than 0.05). Protein gain and composition of weight gain was very similar in both groups (2.0 +/- 0.4 versus 2.1 +/- 0.4 g protein/kg/d; 3.5 +/- 1.1 versus 3.3 +/- 1.4 g fat/kg/d in SGA's and AGA's respectively). However, the rate of protein synthesis was significantly lower in SGA's (7.7 +/- 1.6 g/kg/d) as compared to AGA's (9.7 +/- 2.8 g/kg/d; P less than 0.05). It is concluded that SGA's have a more efficient protein gain/protein synthesis ratio since for the same weight and protein gains, SGA's show a 20 per cent slower protein turnover. They might therefore tolerate slightly higher protein intakes. Postconceptional age seems to be an important factor in the regulation of protein turnover.

Blood Urea Nitrogen↗

Periventricular leucomalacia and neurodevelopmental outcome in preterm infants.

During an 18 month period, 120 preterm infants of 34 weeks' gestation or less were prospectively examined for periventricular leucomalacia (PVL) by cerebral ultrasound. Neurological and developmental assessment was carried out at 18 months of age corrected for prematurity in 82 surviving neonates. The developmental outcome (Griffiths development quotient) was above 80 and similar in infants with normal scans (n = 41), isolated periventricular-intraventricular haemorrhage (n = 13), and post-haemorrhagic hydrocephalus (n = 4), and no major handicap was diagnosed in these groups. By contrast, the prognosis was variable and poorer in infants with PVL (n = 24) and depended on the extent and site of the lesion. Infants with frontal PVL (n = 13) developed normally. Major sequelae (n = 8) were closely related to frontal-parietal PVL and frontal-parietal-occipital PVL and could be ascribed to the presence of cysts as well as to a persistent hyperechogenic ultrasonographic PVL appearance. A relation between size and site of the lesion and type and severity of the handicap was established.

Developmental Disabilities↗